The present invention relates to material handling and, in particular, to methods and apparatuses for conveying packages and a mechanism for controlling the location of packages on a conveyor.
It is conventional to convey large numbers of packages at high speed, especially in the parcel delivery industry, wherein the packages are sorted according to desired categories. The efficiency with which the packages are handled can be seriously diminished when jam-ups of packages occur that require that conveyor lines be shut down until the jam has been cleared.
While a jam-free conveyance of packages along the straight flights of a conveyor is relatively easily accomplished, problems can occur at turns where wide packages present a serious risk of jamming. The sharper the turn, the greater the risk.
Measures to minimize this risk have been taken, such as the use of unscrambling conveyors which comprise driven rollers whose axes extend obliquely relative to the direction of conveyance. As a result, packages are caused to be displaced laterally toward one side of the conveyor and become aligned behind one another.
Notwithstanding the success of such unscrambling conveyors, it can still occur that a package exits the unscrambling conveyor possessing a width which exceeds a maximum width for jam prevention at downstream turns. Also, two packages may exit the unscrambling conveyor while traveling abreast and thereby presenting a combined width which is large enough to create problems at downstream turns.
It would be desirable, therefore, to provide a mechanism for alleviating that problem.